When Parcely receives message which has list, it raises an error.

[narusemotoki]

Traceback (most recent call last):
  File "/usr/local/lib/python3.6/site-packages/falcon-1.4.1-py3.6.egg/falcon/api.py", line 244, in __call__
    responder(req, resp, **params)
  File "/usr/local/lib/python3.6/site-packages/parsely-0.7.0-py3.6.egg/parsely/__init__.py", line 247, in on_post
    kwargs=_validate(self._recurse(message, preprocessors), validation),
  File "/usr/local/lib/python3.6/site-packages/parsely-0.7.0-py3.6.egg/parsely/__init__.py", line 177, in _validate
    if arg_type != Any and not isinstance(value, arg_type):
  File "/usr/local/lib/python3.6/typing.py", line 1161, in __instancecheck__
    return issubclass(instance.__class__, self)
  File "/usr/local/lib/python3.6/typing.py", line 1147, in __subclasscheck__
    raise TypeError("Parameterized generics cannot be used with class "
TypeError: Parameterized generics cannot be used with class or instance checks

>>> isinstance([], typing.List[str])
Traceback (most recent call last):
  File "<input>", line 1, in <module>
    isinstance([], typing.List[str])
  File "/usr/lib/python3.6/typing.py", line 1161, in __instancecheck__
    return issubclass(instance.__class__, self)
  File "/usr/lib/python3.6/typing.py", line 1147, in __subclasscheck__
    raise TypeError("Parameterized generics cannot be used with class "
TypeError: Parameterized generics cannot be used with class or instance checks